Gonçalves PJ, Bezerra FC, Almeida LM, Alonso L, Souza GRL, Alonso A, Zílio SC, Borissevitch IE. Effects of bovine serum albumin (BSA) on the excited-state properties of meso-tetrakis(sulfonatophenyl) porphyrin (TPPS
4).
Eur Biophys J 2019;
48:721-9. [PMID:
31549191 DOI:
10.1007/s00249-019-01397-w]
[Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 02/07/2023]
Abstract
To infer changes in the photophysical properties of porphyrins due to complexation with albumin, a combination of Z-scan and conventional spectroscopic techniques was employed. We measured the characteristics of excited states of meso-tetrakis(sulfonatophenyl) porphyrin bound to bovine serum albumin and observed that the binding reduces the intersystem crossing quantum yield and increases the internal conversion one. A reverse saturable absorption process was observed in the nanosecond timescale. These results are important for prediction of the efficiency of this complex in medical and optical applications, because associating porphyrins to proteins enables better accumulation in tumors and improves its stability in optical devices, but at the same time, decreases its triplet quantum yield.
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